1. Field of the Invention
The present invention relates to blends of curable fluoroelastomers and thermoplastic fluoropolymers having improved tensile strength and tear strength and the process of making them by melt blending, followed by compounding with fillers and curing agents, at below 100.degree. C., and curing the fluoroelastomer.
2. Prior Art
U.S. Pat. No. 3,484,503 discloses single phase blends of an elastomeric copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether) with a thermoplastic copolymer of tetrafluoroethylene. The elastomeric component does not contain a cure site and so the composition cannot be crosslinked.
U.S. Pat. No. 3,987,126 discloses blends of a curable fluoroelastomer with a fluoroelastomer having ether links in the polymer chain having perfluoroalkyl end group containing at least one terminal iodo cure site.
U.S. Pat. No. 4,413,094 discloses a co-vulcanizable fluoroelastomer blend of tetrafluoroethylene/perfluoro(methylvinyl-ether)/cure-site monomer terpolymer and hexafluoropropylene oxide/cure-site monomer copolymer.